Shuttle touches down in Florida

(CNN) -- Space shuttle Atlantis returned home to the Kennedy Space Center in Florida.

The shuttle landed at about 11:39 p.m. EDT after a 24-hour delay blamed on poor weather at the landing facility.

The Atlantis crew, which has spent almost two weeks in orbit, delivered and installed a $164 million air lock to the international space station, allowing its residents to venture into space without the assistance of visiting space shuttles.

Rains near Cape Canaveral prevented the shuttle from landing shortly after midnight as originally planned. But the clouds cleared during the day and NASA spokesperson George Diller said conditions should be acceptable for the Tuesday night landing.

Atlantis had enough fuel and supplies, if needed, to remain in orbit several more days. NASA has a backup landing site at Edwards Air Force Base in California, a desert area with consistently sunny skies. But the agency prefers to not to use it because ferrying the shuttle back to Florida costs about $1 million.

Opening a door on Alpha

The five Atlantis astronauts worked eight days at the space station, setting up a 6.5-ton air lock that will permit Alpha crews to venture from the station in U.S. or Russian spacesuits.

The Atlantis crew after landing

Previously, Alpha residents would have had to rely on Russian suits and a much more cramped portal into space.

The air lock construction job was the first in which Alpha's new robotic arm was used. Despite nagging problems during earlier testing, the $600 million crane performed well.

But a flurry of missteps onboard Atlantis and Alpha forced NASA to extend the mission. A computer crashed. Water spilled. Alarms went off. Air leaked from the air lock. Battery acid appeared to have oozed from a spare spacesuit.

Alpha crew to come home soon

The shuttle visitors were the first to the space station in more than two months. But the Alpha residents should greet their next guests soon. In early August, the shuttle Discovery is expected to bring a fresh crew to the three-story complex and return with the old one.

Alpha's new air lock juts off the side of the space station

The Atlantis mission marked a major milestone in space station construction. With the new air lock installed and the 58-foot (17-meter) robotic arm operational, Alpha crews can install station parts that arrive via unmanned cargo ships, without help from shuttle crews.

A project of the United States, Russia, Europe and Japan, the expanding international space station could eventually cost more than $60 billion.